<!doctype html>
<html lang="en">
<head>
    <title>Shader - Height Map (Three.js)</title>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
    <link rel=stylesheet href="css/base.css"/>
</head>
<body>

<script src="js/Three.js"></script>
<script src="js/Detector.js"></script>
<script src="js/Stats.js"></script>
<script src="js/OrbitControls.js"></script>
<script src="js/KeyboardState.js"></script>
<script src="js/THREEx.FullScreen.js"></script>
<script src="js/THREEx.WindowResize.js"></script>

<!-- ---------------- Custom Shader Code ------------------------ -->
<script id="vertexShader" type="x-shader/x-vertex">
uniform sampler2D bumpTexture;
uniform float bumpScale;

varying float vAmount;

void main() 
{ 
	vec4 bumpData = texture2D( bumpTexture, uv );
	
	vAmount = bumpData.r; // assuming map is grayscale it doesn't matter if you use r, g, or b.
	
	// move the position along the normal
    vec3 newPosition = position + normal * bumpScale * vAmount;
	
	gl_Position = projectionMatrix * modelViewMatrix * vec4( newPosition, 1.0 );
}
</script>

<!-- fragment shader a.k.a. pixel shader -->
<script id="fragmentShader" type="x-shader/x-vertex"> 

varying float vAmount;

void main() 
{
	vec3 water = (smoothstep(0.01, 0.25, vAmount) - smoothstep(0.249, 0.25, vAmount)) * vec3(0.0, 0.0, 1.0);
	vec3 sandy = (smoothstep(0.20, 0.27, vAmount) - smoothstep(0.28, 0.31, vAmount))  * vec3(0.9, 0.9, 0.5);
	vec3 grass = (smoothstep(0.28, 0.32, vAmount) - smoothstep(0.35, 0.40, vAmount))  * vec3(0.0, 0.6, 0.0);
	vec3 rocky = (smoothstep(0.30, 0.50, vAmount) - smoothstep(0.40, 0.7, vAmount))   * vec3(0.8, 0.4, 0.2);
	vec3 snowy = (smoothstep(0.50, 0.65, vAmount))                                    * vec3(0.8, 0.8, 0.8);
	gl_FragColor = vec4(water + sandy + grass + rocky + snowy, 1.0);
}  
</script>
<!-- ----------------------------------------------------------- -->

<!-- Code to display an information button and box when clicked. -->
<script src="js/jquery-1.9.1.js"></script>
<script src="js/jquery-ui.js"></script>
<link rel=stylesheet href="css/jquery-ui.css" />
<link rel=stylesheet href="css/info.css"/>
<script src="js/info.js"></script>
<div id="infoButton"></div>
<div id="infoBox" title="Demo Information">
This three.js demo is part of a collection at
<a href="http://stemkoski.github.io/Three.js/">http://stemkoski.github.io/Three.js/</a>
</div>
<!-- ------------------------------------------------------------ -->

<div id="ThreeJS" style="position: absolute; left:0px; top:0px"></div>
<script>
/*
	Three.js "tutorials by example"
	Author: Lee Stemkoski
	Date: July 2013 (three.js v59dev)
 */

// MAIN

// standard global variables
var container, scene, camera, renderer, controls, stats;
var keyboard = new KeyboardState();
var clock = new THREE.Clock();

// custom global variables
var mesh;

init();
animate();

// FUNCTIONS 		
function init() 
{
	// SCENE
	scene = new THREE.Scene();
	// CAMERA
	var SCREEN_WIDTH = window.innerWidth, SCREEN_HEIGHT = window.innerHeight;
	var VIEW_ANGLE = 45, ASPECT = SCREEN_WIDTH / SCREEN_HEIGHT, NEAR = 0.1, FAR = 20000;
	camera = new THREE.PerspectiveCamera( VIEW_ANGLE, ASPECT, NEAR, FAR);
	scene.add(camera);
	camera.position.set(0,100,400);
	camera.lookAt(scene.position);	
	// RENDERER
	if ( Detector.webgl )
		renderer = new THREE.WebGLRenderer( {antialias:true} );
	else
		renderer = new THREE.CanvasRenderer(); 
	renderer.setSize(SCREEN_WIDTH, SCREEN_HEIGHT);
	container = document.getElementById( 'ThreeJS' );
	container.appendChild( renderer.domElement );
	// EVENTS
	THREEx.WindowResize(renderer, camera);
	THREEx.FullScreen.bindKey({ charCode : 'm'.charCodeAt(0) });
	// CONTROLS
	controls = new THREE.OrbitControls( camera, renderer.domElement );
	// STATS
	stats = new Stats();
	stats.domElement.style.position = 'absolute';
	stats.domElement.style.bottom = '0px';
	stats.domElement.style.zIndex = 100;
	container.appendChild( stats.domElement );
	// LIGHT
	var light = new THREE.PointLight(0xffffff);
	light.position.set(100,250,100);
	scene.add(light);
	// FLOOR
	var floorTexture = new THREE.ImageUtils.loadTexture( 'images/checkerboard.jpg' );
	floorTexture.wrapS = floorTexture.wrapT = THREE.RepeatWrapping; 
	floorTexture.repeat.set( 10, 10 );
	var floorMaterial = new THREE.MeshBasicMaterial( { map: floorTexture, side: THREE.DoubleSide } );
	var floorGeometry = new THREE.PlaneGeometry(1000, 1000, 10, 10);
	var floor = new THREE.Mesh(floorGeometry, floorMaterial);
	floor.position.y = -0.5;
	floor.rotation.x = Math.PI / 2;
	//scene.add(floor);
	// SKYBOX
	var skyBoxGeometry = new THREE.CubeGeometry( 10000, 10000, 10000 );
	var skyBoxMaterial = new THREE.MeshBasicMaterial( { color: 0x9999ff, side: THREE.BackSide } );
	var skyBox = new THREE.Mesh( skyBoxGeometry, skyBoxMaterial );
	scene.add(skyBox);
	
	////////////
	// CUSTOM //
	////////////
	
	// texture used to generate "bumpiness"
	var bumpTexture = new THREE.ImageUtils.loadTexture( 'images/heightmap.png' );
	bumpTexture.wrapS = bumpTexture.wrapT = THREE.RepeatWrapping; 
	// magnitude of normal displacement
	var bumpScale   = 200.0;
	
	// use "this." to create global object
	this.customUniforms = {
		bumpTexture:	{ type: "t", value: bumpTexture },
		bumpScale:	    { type: "f", value: bumpScale },
	};
	
	// create custom material from the shader code above
	//   that is within specially labelled script tags
	var customMaterial = new THREE.ShaderMaterial( 
	{
	    uniforms: customUniforms,
		vertexShader:   document.getElementById( 'vertexShader'   ).textContent,
		fragmentShader: document.getElementById( 'fragmentShader' ).textContent,
		side: THREE.DoubleSide
	}   );
		
	var planeGeo = new THREE.PlaneGeometry( 1000, 1000, 120, 120 );
	var plane = new THREE.Mesh(	planeGeo, customMaterial );
	plane.rotation.x = -Math.PI / 2;
	plane.position.y = -100;
	scene.add( plane );

	
}

function animate() 
{
    requestAnimationFrame( animate );
	render();		
	update();
}

function update()
{
	if ( keyboard.pressed("z") ) 
	{	  
		// do something
	}
	
	controls.update();
	stats.update();
}

function render() 
{
	renderer.render( scene, camera );
}

</script>

</body>
</html>
